Ideas to stabilize humidity in a forced air incubator

Hello, I'm trying to hatch my very first batch of eggs with my new incubator (forced air) and I'm able to peg and hold the 99.5 temp consistently, but my humidity is swinging from 40% with no water in the channels to 85% when I only fill one small channel. If the channel were even smaller I would be able to get less surface area involved, but do not know if anyone would have any ideas before I start manipulating my styrofoam on my new incubator?

My incubator is a Farm Innovators 4200, if that helps. And I'm incubating coturnix quail eggs. This is the end of the first 24 hrs with the eggs in the incubator, so hopefully I've not dried them out or turned them into a swamp with the humidity swings. I did operate my incubator prior to adding the eggs (8+ hrs), but never got the humidity to stabilize.